In order to achieve an improvement in terms of comfortability of houses in cold districts, and comfortability of houses in warm districts during a cold season, a floor heating technique for heating a house from a floor in the house has conventionally been proposed and put into practical use. For example, in a case of a single house, a floor heating panel is incorporated between floor joists and a floor board, or installed on a surface of a backing plywood floor laid on floor joists, and the like. In a multiple dwelling house, such as an apartment house, a method in which a floor heating panel is laid directly on an upper surface of a floor slab, or on a surface of a backing plywood floor laid on a floor slab, is adopted.
As an example of a floor heating panel of this type, there has been proposed a structure which includes as a base an elongated plate-like member of foam synthetic resin, wherein grooves are formed in one surface of this base, and a heat carrier flexible tube is embedded in these grooves with the surface being covered with a flexible thin plate such as an aluminum foil. A floor heating panel of such a structure is prepared so as to generally exhibit, for example, a rectangular configuration having a length of 300 cm and a width of 250 cm in accordance with a size of a place of installation. When, however, a length or a width is not less than 200 cm, the floor heating panel is folded so as to be reduced in width by at least half before it is packaged, stored, and transported. Usually, after a folded floor heating panel has been brought to a place of installation, the folded panel is developed for laying.
As an example of such a conventional floor heating panel, which can be folded in a width direction, there has been proposed a floor heating panel having a detachable folding portion. The panel consists of at least two plate-like members with grooves formed therein, arranged adjacent to each other. Heat carrier flexible tubes are arranged in the grooves, and a flexible thin plate is attached to surfaces of the plate-like members, excluding portions where the plate-like members are adjacent to each other. Folding is possible after removing the tubes from the grooves formed near the portions where the plate-like members are adjacent to each other (See Japanese Utility Model Application Laid-Open No. 5-27514).
However, in this construction, no flexible thin plate is attached to portions of the plate-like members from which the tubes are detached, resulting in a rather poor radiation effect of the floor heating panel as a whole. Moreover, there is a danger of the tubes detached from the grooves being pressurized and crushed between folded plate-like members. Further, when storing this floor heating panel in a folded state, it is necessary to shift adjacent plate-like members with respect to each other so as to prevent the tubes from buckling, so that a storage operation is rather difficult to perform. Further, it is necessary to perform positioning on a plurality of plate-like members when laying them, which means a laying operation is also rather difficult to perform.
As an example of a floor heating panel which is free from a problem of a poor radiation effect and a danger of tube breakage at a time of folding, there has been proposed a floor heating panel in which at least two plate-like members, with grooves, are arranged adjacent to each other to form a separable folding portion, and in which a fit-in portion that allows mounting and detachment is provided at one end with respect to a length direction of a side surface portion of a plate-like member forming the folding portion (See Japanese Patent Laid Open No. 10-89712). This floor heating panel can be folded in a width direction, but cannot be folded in a length direction, so that a problem in that a storage operation and a laying operation are rather difficult to perform has not been solved.
As another example of a foldable floor heating panel, there has been proposed a folding (windable) floor heating panel in which several elongated narrow plate-like members, each having there inside a hollow portion, are connected by a flexible thin plate. The hollow portions for tube arrangement near connecting portions are relatively wide, and a heat carrier flexible tube is arranged in a meandering state in the hollow portions of these plate-like members (See Japanese Patent Laid Open Nos. 8-261485 and 10-321344). However, in this construction also, folding (winding) is only possible in one of a length direction and width direction, which means the panel is rather difficult to handle at a time of packaging, storage, transportation, or laying.
In view of the above problems in the prior art, after careful study to provide a floor heating panel free from such problems, the present inventor has succeeded in completing the present invention.
Thus, it is an object of the present invention to provide a foldable floor heating panel constituted from small plate-like members such that the foldable floor heating panel can be folded along each small plate-like member in both longitudinal and lateral directions, so that a folding operation and a developing operation are easy to perform, and wherein the heating panel is very easy to handle at a time of packaging, transportation, storage, or laying.